How severe is CVE-2025-39873?

CVE-2025-39873 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-39873 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-39873?

CVE-2025-39873 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-39873?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-39873 have an EU (EUVD) identifier?

Yes. CVE-2025-39873 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-30865.

When was CVE-2025-39873 published?

CVE-2025-39873 was published on 2025-09-23 and last updated on 2026-06-17.

CVE-2025-39873

CVE-2025-39873 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (4th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-30865
Weakness: CWE-416
Affected product: Linux Linux Kernel
Published: 2025-09-23
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB can_put_echo_skb() takes ownership of the SKB and it may be freed during or after the call. However, xilinx_can xcan_write_frame() keeps using SKB after the call. Fix that by only calling can_put_echo_skb() after the code is done touching the SKB. The tx_lock is held for the entire xcan_write_frame() execution and also on the can_get_echo_skb() side so the order of operations does not matter. An earlier fix commit 3d3c817c3a40 ("can: xilinx_can: Fix usage of skb memory") did not move the can_put_echo_skb() call far enough. [mkl: add "commit" in front of sha1 in patch description] [mkl: fix indention]

Frequently asked questions

What is CVE-2025-39873?: In the Linux kernel, the following vulnerability has been resolved: can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB can_put_echo_skb() takes ownership of the SKB and it may be freed during or after the call. However, xilinx_can xcan_write_frame() keeps using SKB after the call. Fix that by only calling can_put_echo_skb() after the code is done touching the SKB. The tx_lock is held for the entire xcan_write_frame() execution and also on the can_get_echo_skb() side so the order of operations does not matter. An earlier fix commit 3d3c817c3a40 ("can: xilinx_can: Fix usage of skb memory") did not move the can_put_echo_skb() call far enough. [mkl: add "commit" in front of sha1 in patch description] [mkl: fix indention]
How severe is CVE-2025-39873?: CVE-2025-39873 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-39873 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (4th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-39873?: CVE-2025-39873 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-39873?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-39873 have an EU (EUVD) identifier?: Yes. CVE-2025-39873 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-30865.
When was CVE-2025-39873 published?: CVE-2025-39873 was published on 2025-09-23 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

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